The present invention relates to a suction nozzle unit for a vacuum cleaner, and more particularly, a suction nozzle unit for a vacuum cleaner having a mechanism for lifting up a front portion of the suction nozzle unit.
The invention can perhaps be best understood by first considering a conventional vacuum cleaner as illustrated in FIGS. 5 to 7. Referring to FIG. 5, a conventional vacuum cleaner 90 is comprised of a cleaner body 91, inside of which a suction fan (not shown) and a filter (not shown) are installed, a suction nozzle unit 101 for sucking dust and debris from a surface to be cleaned, and a suction pipe 93 and a connection hose 97, both of which connect the suction nozzle unit 101 to the cleaner body 91.
The cleaner body 91 is provided with a pair of rollers 92 and the suction nozzle unit 101 is provided with a pair of front wheels 109 and a pair of rear wheels 106. The roller 92, the front and rear wheels 109 and 106 respectively enable the cleaner body 91 and the suction nozzle unit 101 to be moved over the surface to be cleaned. A handle 95 for a user is connected between the suction pipe 93 and the connection hose 97. By grasping the handle 95, the user can move the suction nozzle unit 101 on the surface to be cleaned. When the suction nozzle unit 101 is moved, dust and debris attached to the surface to be cleaned are sucked into the suction nozzle unit 101 by the suction force from the suction fan (not shown) installed in the cleaner body 91 and then moved into the cleaner body 91 through the suction pipe 93 and the connection hose 97.
Referring to FIGS. 6 and 7, the conventional suction nozzle unit 101 is comprised of a casing 103 defining the outer appearance of the suction nozzle unit 101, the above mentioned pair of front wheels 109 and pair of rear wheels 106, for enabling the user to move the suction nozzle unit 101 over the surface to be cleaned, and a connector 107 to which the aforementioned suction pipe 93 is coupled.
The casing 103 is comprised of a lower casing 110 and an upper casing 120 coupled to the lower casing 110. In the front bottom part of the lower casing 110 is formed a suction inlet 111 for sucking dust and debris from the surface to be cleaned. In the back of the suction inlet 111 are located a pair of oppositely disposed, substantially L-shaped partitioning walls 124. Between side wall portions 124a of the partitioning walls 124 is formed a suction duct 113 which serves as a passageway for the dust and debris sucked through the suction inlet 111. The top of the suction duct -113 is covered with the duct cover 123. In the back of the suction duct 113 is positioned a connector receiving part 125, with which the connector 107 is rotatably coupled.
Between a front wall 110a and side walls 110b of the lower casing 110, and front wall portions 124b of the partitioning walls 124 is formed a brush receiving part 115 in which a brush member 127 for removing the dust and debris from carpet pile or fiber 89 of a carpet 87 is rotatably installed. The brush member 127 is rotated by a brush motor (not shown).
In the front and back sides of the lower casing 110 are respectively installed wheel coupling parts 117 with which the front and rear wheels 109 and 106 are coupled.
With this configuration, the suction nozzle unit 101 sucks dust and debris from the surface to be cleaned by the suction force generated from the suction fan (not shown) installed in the cleaner body 91 and through the suction inlet 111. The dust and debris vacuumed or sucked up from the carpet is transported into the cleaner body 91 through the suction duct 113 and the connector 107.
A disadvantage of this kind of a conventional suction nozzle unit 101 is that the height of the bottom face of the lower casing 110 relative to the surface to be cleaned is so small that the suction inlet 111 closely contacts the surface to be cleaned, and therefore, movement of the suction nozzle unit 101 is restricted depending on the shape or nature of the surface to be cleaned. This is a particular problem in cleaning the deep pile carpet 87 depicted in FIG. 7, wherein all or a part of the carpet fibers 89 of the carpet 87 may be directed toward the suction inlet 111 of the lower casing 110, thereby causing resistance against the movement of the suction nozzle unit 101. Further, in the case of the deep pile carpet 87, i.e., a carpet having relatively long carpet fibers as indicated 89, stronger resistance will be caused against the movement of the suction nozzle unit 101. For all these reasons, movement of the suction nozzle unit 101 can be difficult when vacuuming deep pile carpets. In addition, the user must exert himself or herself more vigorously to move the suction nozzle unit 101 in order to overcome the resistance against movement exerted on the suction nozzle unit 101, and as a consequence, the job of vacuuming can become tiring and burdensome.
An important object of the present invention is to overcome the above-described problems and, to this end, a suction nozzle unit is provided for a vacuum cleaner which enables easier and more convenient vacuuming by reducing the resistance against the movement of the suction nozzle unit so as to enhance the movability thereof.
This object of the present invention is accomplished through the provision of on an improved suction nozzle unit for a vacuum cleaner comprising a casing including a suction inlet, a pair of front wheels at the front of the casing and a pair of rear wheels at the rear of the casing, wherein the suction nozzle unit further comprises a shaft pin for rotatably supporting the front wheels, and means for moving the casing up and down relative to the shaft pin so as to vary the height of the front end of the casing relative to the surface to be vacuumed(e.g., a carpet).
Preferably, the moving means comprises a rotation shaft extending parallel to the shaft pin and mounted in the casing for movement up and down along with the casing, a rotation arm connecting the rotation shaft and the shaft pin together, and means for rotating the rotation shaft relative to the shaft pin to move the casing up and down.
Preferably, the rotating means comprises an operating lever extending radially from the rotation shaft, and a driving means for rotating the operating lever.
Preferably, the driving means comprises an adjusting knob disposed on the casing, having a shaft with a spiral groove formed in the outer circumference thereof and a handle provided at s first end of the shaft for rotating the shaft, and a slider member having a spiral rib on the inner circumference thereof engaging the spiral groove of said shaft and being mounted so as to move up and down along said shaft, responsive to rotation of said shaft, to thereby cause rotation of the operating lever.
Preferably, an engagement projection is provided at one end of the slider and is adapted to be engaged with the operating lever.
Preferably, the driving means further comprises a coil spring having a first end connected to the operating lever and a second end connected to a bottom wall of the casing, for resiliently biasing the operating lever in a upwardly direction away from the said bottom wall.
Preferably, the driving means further comprises rotational angle adjusting means for adjusting the rotational angle of the shaft. Preferably, the rotational angle adjusting means includes an adjusting protrusion extending outwardly from the second end of the shaft, and an adjusting protrusion receiving member provided in the casing and including a plurality of adjusting grooves for receiving the adjusting protrusion.
In accordance with a further aspect of the invention, a vacuum cleaner suction nozzle is provided wherein the unit comprises: a casing having a front end and a rear end, and including first and second front wheels at the front end of the casing, and at least one wheel located at the rear end of the casing and defining a rotation axis; first and second shaft pins for supporting said first and second front wheels for rotation about said first and second shaft pins, respectively; a shaft connecting said shaft pins together and being rotatable about said shaft pins; coupling means for coupling said shaft to said casing so that rotation of said shaft about said shaft pins produces pivoting of the casing about the axis of said at least one rear wheel and resultant elevation of the front end of said casing; and operator controlled control means for providing selected rotation of said shaft about said shaft pins to produce selected elevation of said front end of said casing.
Further features and advantages of the present invention will be set forth in, or apparent from, the detailed description of preferred embodiments thereof which follows.